Trawling-net.



C. H. KAHRS.

TRAWLING NET.

APPLICATION FILED MAY 24, 1912.

Patented May 6, 1913.

CHRISTIE' IEIBERG KAHRS, 0F CHRISTIANIA, NORWAY.

TRAwLING-NET.

Speciziation of Letters Patent. Applicbt'iot led Hay 24, 1912. :Seriallo. 099,418.

Patented May e, 1913.

'o all whom t may concern.

Be it known. that I, CHRIs'mN HEIBERG KAHRS, a subject of the King ofNorway, residing at hristiania, Norway, have invented certain new anduseful Improvements in Trawling-Nets; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as' will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to letters or figures of reference marked thereon, which form a partof this specification.

My invention relates to trawling nets and its object is 'to so constructthe net that in spite of the pull exerted u on it in an upwarddirection, during traw ing, the net will be pulled downward. This objectI attain by weaving the sloping bottom portion of the net more closelythan the other portion, whereby the sloping bottom portion issubjectedto a greater pressure by the water than the other portion, whichpressure will act to pull the net down.

In` the drawing, Figure 1 illustrates a side elevation of a trawling netembodying my invention, Fig. 2 is a top plan view of the same, Fig. 3 isa front view, and Fig. 4 a detail view.

The main portion of the trawl consists ofan irregular cone, the upperstraight line a of which is held substantially horizontal, while thelower portion b slopes downward.

The top portion, or point, 1s woven, as is usual, more strongly and moreclosely than the rest.

The net is kept expanded during the trawling by means of the arms 0,(Z,attached to the circumference of the opening, boards e, f being fixed tosaid arms. The warps are secured to these boards, as shown in Figs. 2and 4, in such a way, that the `pressure of the water tends to press theboards outward. The connection between the boards e, f, and

` the side of the trawl is formed by means of triangular pieces of netZ, with a view to distributing the pull over as large as pos sible apart of the net at the circumference of its opening, so as to make theopening circular, or nearly circular.

I The sloping bottom portion b is made of a net having much finer meshesthan the other net of the trawl. The meshes of this fine net areextraordinarily long and narrow, the length. and width of said meshesbeing approximately in proportion 4:1. The object of making portion ofthe trawl smaller than the rest of the meshes is to provide acomparatively large area of resistance to the water, as the net ispulled along, whereby the trawl is pulled deeper down into the water.yThe meshes are made long and narrow, so that -no substantial resistanceis ofered against forward movement.

A round pole g is attached to the lower end ofthe trawl. The lower partof this pole is made of iron' or other heavy metal, the rest being wood,or other light material.

the meshes of this A rope it, the length of which is' equal to thediameter' of the net opening, is attached to the same point of the loweredge of the trawl, where the said pole is attached. The rope h is guidedthrough a thimble n, fixed to the upper edge of the net opening, and afloat z' is fastened to the free end of the rope, the buoyancy of saidiioat balancing approximately the weight of the pole g.

In shallow water, when the trawl gets too near the bottom, the pole g,with its heavy end, will touch. As soon, however, as the weight of thepole is thus no longer supported by the float, the latter will lift thefront part of the trawl, until pole g assumes a substantially verticalposit-ion,

ljust touching bottom. As the rope 71. isl attached to the front part ofthe trawl at the bottom thereof, this part will be lifted up, so that,to a great extent, the lower portion will lose its sloping position,whereby, of course, the tendency of pulling the trawl downward becomesdiminished. -It will be seen, therefore, that the trawl will rise assoon as the pole g touches bottom, and thus, the trawling net itselfwill not touch bottom.

In order notto interfere with the rising of the trawl I make the boardse, f of a frame o, consisting of rigid material, for instance, wood,covered by'another material p, such as thin sheet metal, fabric, or thelike. In orderto hold this cover against the pressure of the water, theopening of the frame front part of the sloping bottom.

ness, a portion of the cover is broken away, to show the net r. Suc akind of board will be much lighter than an ordinary board for the samepurpose and yet will be of the same strength.

' I claim 1. In crawling nets the combination With a closely wovenbottom ortion sloping down in the direction of raft, of a p ole made oflight material and having a heavy end and secured with its light end tothe 2. 'In crawling nets the combination with a closely woven bottomportion sloping in the direction of draft, of a pole made of lightmaterial and havin a heavy end and secured with its light en to thefront part of the slo ing bottom, and a rolpe also secured to t e rontpart of the s oping botmemes tom, and a thimble in the upper part of thetrawl for guiding said rope.

3. In travvling nets the combination with a closely woven bottom portionsloping in the direction of draft, of apole made of light material andhavin a heavy end and secured with its light en to the front part of theslo ing bottom, and a rope also se cured to t e front part of thesloping bottom, and a thimble 1n the upper part of the trawl for guidingsaid rope, and a float attached to the ro e above the said thimble.

In testimony tat I claim the foregoing as iny invention, I have signedmy name in presence of two subscribing Witnesses.

CHRISTEN HEIBERG KAHRS. Witnesses:

AUG. OLsEN, THS. HERZ.

